A remote controller and a power control method are disclosed. The remote controller includes a voice recognizer a voice recognizer configured to recognize a voice utterance, a user interface configured to receive a user command; and a controller configured to, when a user command is input through the user interface to enter a voice recognition mode, convert a stand-by mode into an active mode, and convert the active mode into the stand-by mode depending on whether the utterance is recognized within a preset critical time. Accordingly, the remote controller, enabling an operation mode of a voice recognition module which recognizes a user voice utterance to be maintained as an active mode, can reduce power unnecessarily consumed.